I don't think that the 70D will be far better than the 60D. The better Chiptechnology will loose a lot of it's capabilities to the fact that the resolution is higher and the pixels are even smaller because the PhaseDetection-AF is next to the Lightsensor. On the papers from Canon the Pixels are about 50% of the former ones... I think we can be lucky if the 70D has a little bit more IQ than the 60D or 700D.
Do we really need more ISO? Infact Canon Sensors have great ISO-Specs. Canon should make other important improvement (better Dynamic Range, get rid of the Bayer-scheme and the AA-Filter etc.). Magic Lantern is more innovative lately than the mother Canon itself.
5DC, 5DM3, 85 1.2L II, 80-200 2.8L, 100 2.8L IS, 14 2.8, 35 1.4, 75-300 IS, 135 1.8, 40STM, 24-85, Helios 44-2, Zeiss Lenses, and real cams like Zenza Bronica ETRSi or Fuji GX680